


Swallowed in Chocolate Cosmos

by RainbowPools



Series: The Flower Vase, Kinktober [25]
Category: Haikyuu!!
Genre: Alternate Universe - Supernatural Elements, Exorcist Tsukishima Kei, Fluff, Incubus Yamaguchi Tadashi, Kinktober 2020, M/M, Overstimulation, Power Bottom Yamaguchi Tadashi, Public Sex, Roof Sex, Smut, Yamaguchi is such a bad bitch
Language: English
Status: Completed
Published: 2020-12-14
Updated: 2020-12-14
Packaged: 2021-03-10 18:02:14
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,274
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28071393
Author URL: https://archiveofourown.org/users/RainbowPools/pseuds/RainbowPools
Summary: “And can I know the name of my mysterious flirt?” Yamaguchi fluted, backing against the wall and ushering Tsukishima close to him.“Kei Tsukishima,” Tsukishima said, “And yourself?”“I’m Tadashi Yamaguchi,” Yamaguchi chimed, “I can call you Tsukki?” Such a gentle soul to be such a beastly creature. Or perhaps that was all apart of his act, his modus operandi for luring his prey.“I guess..” Tsukishima said, though he wasn’t at all comfortable with the idea. Yamaguchi grinned, sweet, heartwarming, gripping Tsukishima’s waist with one hand.Tsukishima’s mission to exorcise a troublesome incubus by name of Tadashi Yamaguchi takes a veering southern turn, but that isn’t the worst thing that could’ve happened. Tsukki’s still got it under control.... probably.
Relationships: Tsukishima Kei/Yamaguchi Tadashi
Series: The Flower Vase, Kinktober [25]
Series URL: https://archiveofourown.org/series/1997434
Comments: 2
Kudos: 135





	Swallowed in Chocolate Cosmos

**Author's Note:**

> Prompt 25: Overstimulation

It had been a running joke amongst the agents of the Karasuno hunting gild that Tsukishima was frigid. The amounts of mirth gained at the expense of Tsukishima’s underwhelming sex life was becoming ridiculous. _Really ridiculous,_ he thought, as he swiped his thumb over the scroll attached to his waist. He scanned the skyline through his glasses, lighted buildings stacked upon one another, creating an enchanting if not industrial show of illumination in the night sky. The city was always most dangerous at night. Creatures of darkness had their way with the humans at this time, which is why people of the Karasuno hunting guild’s nature were so essential. Tsukishima hardly thought he’d be one of those people, the heroic, self-sacrificial type, but light magic came easy to him and exorcism paid well. Ennoshita had been assigned to taking out a werewolf, a recently turned undergraduate named Tanaka Ryuunosuke. A questionable choice. Ennoshita’s soft heart would probably give out for the poor ole thing. Suga himself would be tackling the vampire coven that had been prowling around the central towns, with plans to kidnapped the eldest son Daichi and manipulate the rest of the family that way. Positively ruthless. Asahi, bless his heart, would be dealing with a quick-footed wraith named Nishinoya. Kageyama would be handling a sun dragon by name of Hinata, shouldn’t be too hard. As for Tsukishima? He was in charge of an incubus, y’know, because he was oh so frigid. He hated his friends. So were the thoughts that occupied his mind as he entered the fifth bar for the night. Incubi and succubi followed lust, so it was safe to assume Yamaguchi would be at one of the town’s hotspots for night life, if Suga’s prediction that the incubi would be hunting tonight was correct. Suga had a description of him too, gathered from a victim that survived a dream with him. He was of average height, slender, freckled, distinct brown eyes and dark olive hair. He definitely didn’t _sound_ all that sexy. Tsukishima glanced around, straining to see through the mass of people as the loud pump of music banged against his eardrums, as opalescent lights spattered the crowded dance floors and exacerbated his inability to see. Tsukishima didn’t hold in his sigh, gaze rolling over the bar, the dance floor, the corners of the walls. _Ahh there._ He spotted him, a lithe figure with dark green hair brushing the back of his neck. It seemed he was already deep into his hunt, chattering up his starry eyed victim. They were tucked into the back corner, Yamaguchi with his hand slowly creeping down his victim’s side. Tsukishima approached. He’d have to help that poor person. 

“Excuse me, is this just a two person event?” Tsukishima asked as he neared. Yamaguchi whipped around, a bit clumsy on his heel, gasping, the edges of his countenance fixed in slight irritation. Tsukishima didn’t look directly at him. Maintain eye contact with an incubus for too long and they could find you in your dreams. That time window varied from person to person, so he was apt to take no chances, peering past Yamaguchi at his victim instead. 

“I’m sorry?” Yamaguchi replied. His voice was softer than what Tsukishima might have thought, soothing, gentle, refreshing, not unlike an early morning drizzle in the scalding month of July. 

“You’ve caught my attention,” Tsukishima said, “I hope you don’t mind if i replace your current partner?” Play an incubus’ game. It was the only way to get close enough to kill. His small scroll was now hidden in his bag, swung across his body. 

“You don’t look like you tried very hard,” Yamaguchi looked Tsukishima up to down. 

“Well, we can’t all look as good as you, can we?” Tsukishima kept his voice light, head tilted at an angle. He caught the incubus blushing in the corner of his eye. An incubus whom was easily flustered. What an interesting combo. Perhaps this would be easier than Tsukishima thought. Yamaguchi’s previous victim had excused themselves to find fun elsewhere, thank goodness. If Yamaguchi were at all displeased with that fact, he didn’t show it, hands cocked on his hips as he said, “Sure, let’s play.”

Tsukishima hummed with a nod, reaching for one of Yamaguchi’s hands. 

“And can I know the name of my mysterious flirt?” Yamaguchi fluted, backing against the wall and ushering Tsukishima close to him. 

“Kei Tsukishima,” Tsukishima said, “And yourself?”

“I’m Tadashi Yamaguchi,” Yamaguchi chimed, “I can call you Tsukki?” Such a gentle soul to be such a beastly creature. Or perhaps that was all apart of his act, his modus operandi for luring his prey.

“I guess..” Tsukishima said, though he wasn’t at all comfortable with the idea. Yamaguchi grinned, sweet, heartwarming, gripping Tsukishima’s waist with one hand. Just a few moments. Tsukishima would have to entertain him for just a few minutes. Just until Yamaguchi was ready to take this somewhere private, he could get him alone, and strike. He’d have to hold himself together during those minutes, too. An incubus’ touch was a tricky thing to resist, but this was far from Tsukishima’s first time handling the like. This would be no different. He pressed himself against Yamaguchi’s smaller frame, dipped his head and touched his lips to his, and all at once, regretted it. This incubus was powerful. For seconds too long, Tsukishima’s mind flashed black. For seconds too long, he forgot who he was and what he was doing. For seconds too long,he felt the most exquisite, absorbing pleasure he had ever felt. He was hyper aware of every curve and lime that carved Yamaguchi’s body, warmed by the spring heat he emitted. The taste of his lips, all soft saccharine tenderness, it had Tsukishima breathless. He tried to pull away for air, but Yamaguchi would let no such thing happen. His small hands were glued to Tsukishima’s back, fingertips gliding seamlessly over the spot betwixt his shoulder blades.

“Skinny,” Yamaguchi murmured against his lips when they finally did break for air.

“You’re one to talk, Yamaguchi,” Tsukishima snorted, absently toying with the folds of Yamaguchi’s shirt. He still wasn’t looking at him.

“There’s no way I’m as skinny as you,” Yamaguchi rolled one shoulder, dragging Tsukishima into another kiss. He glided his tongue over Tsukishima’s lip, asking for permission. Tsukishima hadn’t intended on giving it, but Yamaguchi fit his hands up his shirt, gradually dragging them up his svelte stomach, across the faint dimensions of his chest, thumbs brushing over his nipples, prompting him to gasp, allowing for Yamaguchi’s tongue to slide into his mouth. Tsukishima hated the little moan he gave, as electricity claimed his body. Yamaguchi’s fingers were still moving over his skin. He shuddered. He had to do something. He had to reciprocate or he’d just be another victim. He buried his hands in Yamaguchi’s hair, fingers getting caught in the soft tangles. Yamaguchi moaned though, and it was a very loud hum. He was noisy to be so soft spoken.

“Ever considered investing in a brush?” Tsukishima huffed as he rung his hands free of Yamaguchi’s shaggy locks.

“Ever considered investing in plastic surgery?” Yamaguchi retorted.

“Woah...” Tsukishima withdrew, eyes wide.

“I kid,” Yamaguchi flourished his hand and giggled, “I just wanted you to look at me. Your eyes are so pretty.” He sounded genuinely fascinated. Tsukishima cursed under his breath. This little Yamaguchi was not only spunky but clever.

He kind of liked it.

His eyes, they weren’t the eyes of a monster. They were big, round, wide, a swirl of milk chocolate brown. Tsukishima couldn’t look away. Yamaguchi held his gaze, then he was tugging him back into a kiss. Now Tsukishima really _would_ have to kill him, that or risk losing his soul in a dream. His body heated, an unholy warm temperature, though he couldn’t much complain as he kissed and kissed and kissed Yamaguchi, as Yamaguchi grind his hips against him, as he moved his hand down to cup and knead Tsukishima’s ass. His pleasure magic was swallowing him. Tsukishima understood that as his head got lighter and lighter, as his skin got hotter and hotter, as his erection was practically bursting through his pants. Yamaguchi brought his hand around to grab his length, the warmth of his palm seeping through the fabric. “Are you excited?” he chuckled, delighting in the red coloring Tsukishima’s cheeks. 

“Yes,” Tsukishima answered, leaning, biting the curve of Yamaguchi’s ear, slipping his knee between small, lush thighs and pressing it up against his pulsing crotch. “But you are too,” he whispered into Yamaguchi’s ear. Yamaguchi yipped, a pretty little squirm to his movements as his legs clenched around Tsukishima’s knee. Ahhhh, finally, some control.

“Would you like to leave Tadashi?” Tsukishima asked. Yamaguchi, startled by his first name, nodded.

Tsukishima would not soon forget the time he spent with the incubus. They hadn’t ventured far from the bar. In fact, they just went to the roof, a starless sky above, bustling traffic below. Tsukishima, discretely, while making a show of sliding his pants down, grabbed the scroll in his bag. Yamaguchi was quick, pouncing before Tsukishima could even unroll the scroll. They tumbled to the terrace floor in a fit of grunts and tangled limbs. If Tsukishima was mistaken, and Yamaguchi hadn’t been using his pleasure magic earlier, then he was no doubt using it now. The pair weren’t even touching each other and just his weight, just the way his figure slid over Tsukishima’s, felt good, really good. It wasn’t a feeling he thought he could live without. Yamaguchi held the scroll that had dropped from Tsukishima’s hands. As it was an object of light, it scorched Yamaguchi’s skin as he held it, but he didn’t let go. “Listen,” he shook the scroll, “This thing is scary. I don’t know what I did to you, but I really don’t wanna die. And if I wanted to kill you, I just would’ve made you stare at me and then leave and catch you in your dreams later. I mean, why have sex on a roof when I can tailor the scene to how I want it in your dreamscape? I’m genuinely interested in you. I just came out to have a good time. So, could you like, not try and end my life and let me fuck you? Then you can go on with your night and I’ll go on with mine? Please?” Even wen twinged with aggravation, his voice was still rather enchanting. Even when rigid and alert, the press of his body still felt lovely. Tsukishima wasn’t sure _how_ exactly he came to the conclusion that he did, but he decided that this little Yamaguchi wasn’t lying, and that he likely wasn’t much of a threat anyways. So he agreed. After all, he wanted this. 

“Fine,” tsukishima pursed his lips. Yamaguchi dropped the scroll, touching his lips to the red skin of his palm. With little more delay, he fell into another kiss with Tsukishima. Tsukishima detected a slight hint of maple resonating from Yamaguchi’s flesh as they kissed, his hands sliding up and down his spine. God, just being able to touch this man felt good. The pair indulged a stream of hot, messy kisses as they fumbled from their clothes, the night chill speckling goosebumps over their skin. Tsukishima blinked. Yamaguchi was, quite literally, peppered in freckles, those small blemishes spattering his chest, his shoulders, his tummy, his thighs, his back. He liked them. He sat up to kiss the ones on his shoulder, passing his lips over to the other one, then sliding down to kiss the ones on Yamaguchi’s chest. Yamaguchi trembled, a rouge pink flush spilling down his body. Tsukishima was amazed. It felt good to kiss him like that, too. Yamaguchi climbed into Tsukishima’s lap, wrapping his arms around his neck and kissing him. It was like being caught in a spider web, Yamaguchi’s embrace. He was so small, so weak, and yet Tsukishima thought he’d chafe if he pushed against it. Yamaguchi moaned, again grinding down on Tsukishima. It sparked friction, did little to soothe their erections. Both were getting impatient.

“Can you get yourself ready?” Yamaguchi materialized a condom and a bottle of lube, tossing it in his palm. 

“Oh, you’re doing the penetrating?” Tsukishima sat up to face him. 

“Not at all, but I’d like you to slick up that cock of yours,” a grin fluttered across Yamaguchi’s countenance, “if it’s okay that is. I wanna ride you.”

“Sure, okay,” Tsukishima resigned with a shake of his head. In all honesty, he didn’t quite care how or what they did. He just wanted Yamaguchi to keep touching him. So, while Yamaguchi stretched himself out with lubricated fingers, Tsukishima rubbed lube over his cock.

Tsukishima held his breath, honey brown eyes wide and anticipatory, focused on Yamaguchi as the latter settled himself down onto his cock. Yamaguchi, a ball of silver radiance in the moonlight, expression screwed in concentration as he eased himself down, down, down, until he was fully seated, Tsukishima’s heat pulsing within him, making him sigh. Tsukishima drew a breath, a shiver running down his body. This was a little too good, the pleasure swimming through him at Yamaguchi, Yamaguchi all around him, warm, and soft, and tight. Matters became far more extreme when Yamaguchi begun to move. Tsukishima couldn’t breathe. No he couldn’t breathe at all as Yamaguchi moved up, and down, up and down. Each time their hips would connect, each time Tsukishima would take a sharp gasp, each time an unfathomable bead of pleasure would explode in his body, over his skin, through his chest. Good god what the hell? Incubi should be illegal. Well, he supposed in a way, they were. He acknowledged that he probably shouldn’t have agreed to intercourse with a creature purposed just for pleasure, but it was far too good to regret. It was overwhelming, all that he was feeling, all that he was not. He wasn’t thinking. He didn’t have the capacity to, and as he roamed his hands up and down Yamaguchi’s undulating body, as they met and broke for kisses, he realized, it was too much. Yamaguchi wasn’t particularly quick either. Contrarily his rhythm was soft and steady, and in order for Tsukishima to survive, he’d either need to stop now, or bring him to climax. 

“Tadashi ... please.. go faster,” Tsukishima breathe, ghosting his knuckles over Yamaguchi’s cheek. 

“All right,” Yamaguchi exhaled, lowly, picking up the pace and _oh._ Tsukishima did regret that. He absolutely shouldn’t have asked. Yamaguchi went harder, faster, his pleasure magic mixing with Tsukishima’s own pleasure. Oh it was good, so good, sweetly good, too good. Tsukishima’s blood beat in his ears, body erupting in bliss so great it hurt.

“Tadashi ...” Tsukishima whispered, “I need to come...”

“I’ll try my best for you Tsukki,” Yamaguchi cooed between pants. He sped up, breaths hitching and ragged. He expended more effort, slamming down harder on Tsukishima. Somehow the pleasure got _worse._ Tsukishima quivered with every thrust, body drowning in sweat, in heat, in desire. Sparks sauntered in and out of his vision. Coherent thoughts popped into his brain and then fled, leaving him only with Yamaguchi. Too much, too much, too much. A mantra echoing in his head as his heart hammered. He needed to cum. He needed to cum, communicated in no big way by the lascivious groans tumbling from his lips. He would’ve covered his mouth, only, he couldn’t bring himself to move other than the mechanical upward swing of his hips to meet Yamaguchi’s thrusts, nails biting into the soft flesh at Yamaguchi’s hips. Everything about Yamaguchi was so soft, his hair, his skin, his eyes, his voice. Tsukishima was blessed to experience it, but for fuck’s sake he needed to cum. He needed the agonizing pleasure to end. He was unaware of everything but their bodies and their sounds. He needed release.

“Tadashi!” it was almost a sob. Yamaguchi braced his hands down, onto Tsukishima’s chest, giving his all into his next few thrusts, pouring all his pleasure magic into it.

“Oh.. g-god..” Tsukishima coughed as his culmination finally, finally lapped over him. It was a terrible sensation, terrible as his body rattled. His vision was washed with white, and he felt as though the nothingness that was his brain had exploded into even more nothingness. His body was numb with it, this horrendous pleasure. He wasn’t conscious to the semen splashing onto his stomach, and was only semi-aware of Yamaguchi’s faltering cry and his jerky movements as he climaxed.

“How was that?” Yamaguchi remained in his straddle on Tsukishima , even as they calmed. Tsukishima couldn’t speak, so he pulled Yamaguchi down for a quick kiss instead. Yamaguchi stayed with Tsukishima until he was eased, massaging his neck and shoulders, telling him trashy puns, helping him into his clothes. Tsukishima was sitting on the roof’s edge when his watch started beeping. Yamaguchi jumped at the sound. Then he was taking off into the air, vanishing beneath the black sky. Tsukishima tapped the face of his watch. A holographic panel projected before Tsukishima, partitioning into four different screens that showed the faces of the other Karasuno hunting guild members.

“Hey, how’s everyone doing?” Suga chimed from the screen in the top right corner, mellifluous, a radiant grin gracing his features.

“I got the werewolf,” Ennoshita tipped his camera downward. His screen was below Suga’s, and now one could see the werewolf’s head snug in his lap. The train ride had put him to sleep.

“I don’t wanna kill him,” Ennoshita spoke in hushed tones as he tilted the camera’s view back to his face. He leaned against the window, “Tanaka’s not much older than us. He was turned just a couple weeks ago. He’s gentle, and absolutely terrified. His first blood moon hasn’t happened yet. Maybe prevention is better than the cure?”

Saw it coming.

“We’ll discuss it at length back at HQ. Anyways,” Suga leaned to one side to reveal the cloaked figure bound in his back seat, “I kidnapped Daichi.” Daichi looked pissed, eyes hooded and fangs glinting. His shoulder still bled from where Suga’s dart had struck him.

“I’ve got Hinata,” Kageyama said, and made no effort to prove his claim. “As far as I can tell, he doesn’t have any blood on his hands and can’t fight very well. So he’ll probably end up passing his trial.”

“I got Nishinoya too,” Asahi added.

“Really?” Suga leaned forward in interest. Nishinoya flickered on screen, most of him hidden as he floated behind Asahi. He had one pale hand resting on Asahi’s shoulder, though he likely couldn’t feel it.

“Yeah Uhh, so did I ever tell y’all I had a boyfriend named Nishinoya who mysteriously passed away freshman year of college?”

“No! That’s him?” Sugawara gasped, “Asahi! Why didn’t you tell me!? I wouldn’t have made you do this if I knew you had history with him!”

“It’s okay Suga,” Asahi scratched the back of his head, “i didn’t think it was the same guy. He wasn’t even haunting the place where he died.”

The whole of Karasuno shook their heads.

“Aw, don’t look at me like that,” Asahi sighed, “This is better anyways. I can help him pass on rather than putting him through a painful exorcism.”

“Tsukishima?” Suga turned his attention to the mentioned.

“Oh umm,” Tsukishima fiddled with his fingers, “Yeah um, see.. I failed.”

“...................................................”

He had failed, but when he had next encountered Yamaguchi, it was not in his dreams, but in a coffee shop.

**Author's Note:**

> Thank you all for reading! :)  
> Let me know what you thought in a comment and send some love my way with a kudos.  
> Take care y’all! Eat good and snuggle your loved ones <3


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